Seat device

ABSTRACT

A seat device that can reliably prevent a rotation operation of a seat by a seated person, in a long state where the back of the seat is along a wall. A rotation lock mechanism (60) that can restrain the rotation of a seat (1), a rotation operation unit (200) that performs a release operation of restraint by the rotation lock mechanism (60), and a rotation operation prevention mechanism (210) that disables the release operation in the rotation operation unit (200), when the seat (1) is in the long state are included. The rotation operation prevention mechanism (210) includes an engaging unit (211) provided in the leg stand (11), and an engaged unit (207) that is provided in the rotation operation unit (200) in the movable stand (20), and disables the release operation in the rotation operation unit (200) by being engaged with the engaging unit (211) when the seat (1) is in the long state.

TECHNICAL FIELD

The present invention relates to a seat device that can convert thestate of a seat.

BACKGROUND ART

Conventionally, there are seats of a stool type mounted in, for example,railroad cars, which are long in both directions and can seat aplurality of persons, and are generally installed along walls in cabins.As for this seat, a rotary seat is known that can be rotated about arotation axis in the center of the seat to convert the orientationbetween a long state where the back of the seat is parallel to and alonga wall, and a cross state where the back of the seat is orthogonal tothe wall.

As for such a rotary seat, a seat device has been proposed that includesa sliding mechanism in addition to a rotation mechanism of the seat, andfurther includes a transmission mechanism for interlocking eachmechanism, so that the trajectory (turning radius) of the seat does notinterfere with a wall, when rotating the seat from the long state alongthe wall to the cross state. Refer to, for example, Patent Literature 1.

That is, in the rotary seat, in order to expand the aisle width betweenseats on both sides in a cabin as much as possible to obtain acomfortable space, the rotation axis of the seat is located near a wallin the long state, while the rotation axis of the seat is slid to anaisle side in the cross state, so that the seat does not interfere withthe wall. Therefore, in the rotary seat, in order to prevent theinterference with the wall in the long state, it was necessary toregulate the rotation of the seat by operations by a seated person.

Here, as for a lock mechanism for regulating the rotation of the seat, acommon configuration is a lock pin that is protruded toward the seatside from a fixed side of the seat. In this lock mechanism, as aconfiguration to prevent the seated person from performing a lockrelease operation only in the long state, it was insufficient to merelystore a pedal for performing the lock release operation (refer toparagraph 0062 of Patent Literature 1). Therefore, for example, thetechnology has been known that provides a difference between an electricoperation and a manual operation for the stroke of a lock pin from alocking position to a lock release position (refer to paragraph 0053 ofPatent Literature 2).

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent No. 3431772-   Patent Literature 2: Japanese Patent Laid-Open No. 2018-016217

SUMMARY OF THE INVENTION

However, in conventional rotating apparatuses, in the lock mechanism forregulating the rotation of the seat, the configuration for preventing aseated person from performing the lock release operation only in thelong state includes many parts and is complicated, and it has beendesired to further reduce the cost. Additionally, it has beentroublesome to achieve accuracy between parts, and there has also been arisk that malfunctions occur.

The present invention has been made by focusing on the problems of therelated art as described above, and an object of the present inventionis to provide a seat device that can reliably prevent a rotationoperation of a seat by a seated person when the seat is in a specificstate (long state), with a simple configuration, and without causing anincrease in the cost.

In order to achieve the aforementioned object, in one aspect of thepresent invention,

a seat device that can convert a state of a seat includes

a rotation lock mechanism that can restrain a seat at each of aplurality of rotation angles, the seat being rotatable about a rotationaxis,

a rotation operation unit that performs a release operation of restraintby the rotation lock mechanism, and

a rotation operation prevention mechanism that disables the releaseoperation in the rotation operation unit, when the seat is in a specificstate of one of the rotation angles,

the rotation operation prevention mechanism including

an engaging unit provided on a fixed side of the seat, and

an engaged unit that is provided in the rotation operation unit on amovable side of the seat, and disables the release operation in therotation operation unit by being engaged with the engaging unit when theseat is in the specific state.

With the seat device according to the present invention, in a case wherethe state of the seat can be converted, the rotation operation of theseat can be reliably prevented when the seat is in the specific state,with a simple configuration, and without causing an increase in thecost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a) is a perspective view of an entire seat, FIG. 1(b) is anenlarged perspective view of a reclining operation unit, and FIG. 1(c)is an enlarged perspective view of a rotation operation unit, showing across state of a seat device according to an embodiment of the presentinvention.

FIG. 2(a) is a perspective view of the entire seat, FIG. 1(b) is anenlarged perspective view of the reclining operation unit, and FIG. 1(c)is an enlarged perspective view of the rotation operation unit, showinga long state of the seat device according to the embodiment of thepresent invention.

FIG. 3 is a perspective view showing an internal structure of the seatdevice according to the embodiment of the present invention.

FIG. 4 is a front view showing the cross state of the seat deviceaccording to the embodiment of the present invention.

FIG. 5 is a side view showing the long state of the seat deviceaccording to the embodiment of the present invention.

FIG. 6 is a perspective view showing a leg stand, a movable stand, andan underframe of the seat device according to the embodiment of thepresent invention.

FIG. 7 is a side view showing an initial position of the recliningoperation unit of the seat device according to the embodiment of thepresent invention.

FIG. 8 is a side view showing an operation position of the recliningoperation unit of the seat device according to the embodiment of thepresent invention.

FIG. 9 is a side view showing an initial position of each part of thereclining operation unit of the seat device according to the embodimentof the present invention.

FIG. 10 is a side view showing a state where each part of the recliningoperation unit of the seat device according to the embodiment of thepresent invention is restrained in the initial position to disable theoperation.

FIG. 11 is a side view showing a state where the rotation operation unitof the seat device according to the embodiment of the present inventionis not restrained to disable the operation by the rotation operationprevention mechanism.

FIG. 12 is a side view showing a state where the rotation operation unitof the seat device according to the embodiment of the present inventionis restrained to disable the operation by the rotation operationprevention mechanism.

FIG. 13 is a perspective view showing a rotation lock mechanism of theseat device according to the embodiment of the present invention.

FIG. 14 is a perspective view showing a state where the rotation lockmechanism of the seat device according to the embodiment of the presentinvention is seen from the bottom.

FIG. 15 is an explanatory diagram showing processes of converting theseat into the long state, one cross state, and a reverse cross state inthe seat device according to the embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, an embodiment representing the present invention will bedescribed based on the drawings.

FIG. 1 to FIG. 15 show one embodiment of the present invention.

A seat device 10 according to the present embodiment can convert thestate of a seat 1. Here, the state of the seat 1 is a concept includingnot only the orientation of the seat 1 by rotation, but also the changein the front and back position of the seat 1, etc. Additionally,although the kind of the seat 1 is not particularly limited, a case willbe described below as an example where the seat 1 is applied to a stoolfor two persons mounted in a cabin of a railroad car. Note that, in eachfigure, a slight difference in the shape of an identical part is merelya design change (for example, the difference in the shape of anunderframe 30 in FIG. 1 and FIG. 6 , etc.).

<Outline of Seat Device 10>

As shown in FIG. 6 , the seat device 10 includes a leg stand 11 fixed ona floor surface, a movable stand 20 supported by the leg stand 11 so asto be able to advance and retract in front and back directions, and theunderframe 30 of the seat 1 supported by the movable stand 20 so as tobe rotatable in forward and backward directions. Here, the leg stand 11is “a fixed side of the seat 1”, and the movable stand 20 and theunderframe 30 are “a movable side of the seat 1”. Note that the seatdevice 10 is arranged on the floor surface near a wall (window) in thecabin of the railroad car, and “A” in FIG. 6 is a part of the wallparallel to the moving direction of the railroad car.

In the seat device 10, the underframe 30 of the seat 1 is supported onthe movable stand 20 to be rotatable about a rotation axis via therotation mechanism 40. The movable stand 20 is supported on the legstand 11 together with the rotation mechanism 40 via a sliding mechanism14 so as to be able to advance and retract. Additionally, although anillustration is omitted, the seat device 10 includes an interlockingmechanism in order to interlock the rotation of the seat 1 by therotation mechanism 40 with the advancement and retraction of the seat 1by the sliding mechanism 14.

<Regarding Seat 1>

As shown in FIG. 1 , the seat 1 is formed as a stool for two persons byarranging two seating portions 2 and backrests 3 side by side in bothdirections. A pair of sleeve portions 4 covering the seating portions 2from the sides are provided on both sides of the seat 1. An upper endside of each sleeve portion 4 serves as an armrest 5 that extendssubstantially horizontally in front and back directions. A lower endside of the backrest 3 is supported at a rear end side of the seatingportion 2 via a reclining mechanism 50 (refer to FIG. 3 ) in a tiltablemanner.

<Reclining Mechanism 50>

As shown in FIG. 3 , the reclining mechanism 50 supports the backrest 3with respect to the seating portion 2 in a predetermined angular rangein a tiltable manner. The reclining mechanism 50 includes, for example,a damper 51 such as a gas spring. The damper 51 is configured such thata piston rod 53 is inserted into its cylinder body 52 so as to be ableto protrude, and is arranged on the underframe 30 to be parallel to thefront and back directions. Although the damper 51 is urged in adirection in which the piston rod 53 is housed in the cylinder body 52,the piston rod 53 can be fixed in a state where only an arbitrary amountof the piston rod 53 is projected.

A rear end of the cylinder body 52 is connected to a lower end of aframe 3 a of backrest 3 so as to be able to be pushed and pulled. On theother hand, a tip of the rod 53 that protrudes from a front end of thecylinder body 52 is connected to a proper place of a front end side ofthe underframe 30. With such a damper 51, the backrest 3 can be held atan arbitrary tilt angle. That is, when the damper 51 is a locked state,the piston rod 53 is fixed in a state where only a predetermined amountof the piston rod 53 is projected from the cylinder body 52, so that thebackrest 3 can be held at an arbitrary tilt angle.

When the locked state of the damper 51 is released, the backrest 3returns to a most upright initial position by the biasing force withwhich the piston rod 53 is housed in the cylinder body 52. When a seatedperson presses the backrest 3 backward against the restoring force ofthe damper 51 in this lock released state, the backrest 3 can beadjusted to an arbitrary tilt angle.

Although a detailed description of the lock mechanism of the damper 51is omitted since the lock mechanism is common, a release button 54 forreleasing the locked state is provided near the piston rod 53. Areclining operation unit 100 for pressing this release button 54 torelease the locked state is provided in a front end of the armrest 5.Note that the reclining operation unit 100 corresponds to an “operationunit” of the present invention.

<Reclining Operation Unit 100>

As shown in FIG. 1 , in the reclining operation unit 100, each componentis incorporated and unitized in one housing 101, and is incorporatedinside the front end of the armrest 5. The reclining operation unit 100performs an operation (reclining operation) for tilting the backrest 3by the reclining mechanism 50.

As shown in FIG. 9 and FIG. 10 , the rotation operation unit 100includes an operation lever 104 that is swingably supported by asupporting bracket 102 fixed to the housing 101 via an axis 103. A lowerend side of the operation lever 104 can be swung in front and backdirections with the axis 103, to which an upper end side of theoperation lever 104 is pivotably supported, being the swing center. Theoperation lever 104 is swung between an initial position (refer to FIG.7 ) where the lower end side is housed in the housing 101, and anoperation position (refer to FIG. 8 ) where the lower end side is pulledout forward.

A receiving member 105 of a reclining operation lock mechanism 110,which will be described next, is fixed to a back side of the operationlever 104. One end side of a reclining operation cable 106 extended tothe release button 54 side is connected to the receiving member 105.Here, by pulling the operation lever 104 forward to the operationposition, a link on the release button 54 side is pulled via thereclining operation cable 106 to push the release button 54, and thelocked state of the damper 51 is released. Note that the operation lever104 is normally urged backward to be housed at the initial position viathe reclining operation cable 106.

<Reclining Operation Lock Mechanism 110>

Additionally, the reclining operation unit 100 is provided with thereclining operation lock mechanism 110 that can restrain the recliningoperation unit 100 in an inoperable manner. The reclining operation lockmechanism 110 restrains the reclining operation unit 100 in aninoperable manner, when the seat 1 is in a long state (specific state),which will be described later. Note that the reclining operation lockmechanism 110 corresponds to a “lock mechanism” of the presentinvention.

As shown in FIG. 9 , the reclining operation lock mechanism 110 includesa substantially L-shaped link 112 supported by the housing 101 via anaxis 111 so as to be swingable in the front and back directions. In thelink 112, a lock pin 113 is further supported upward in one end sidefrom the axis 111. The lock pin 113 is disposed such that its upper endside penetrates through a guide hole 102 a in the supporting bracket102, and protrudes in up-and-down directions with the swing of the link112.

The receiving member 105 on the back side of the operation lever 104 isprovided with a lock hole 105 a into which a tip of the lock pin 113 canprotrude and fit, the lock hole 105 a being provided at a lower locationto which the lock pin 113 opposes when the operation lever 104 is in theinitial position. Here, the link 112 that moves the lock pin 113 isnormally urged by a spring member 114 in the clockwise direction aroundthe axis 111 in FIG. 9 , so as to be in a state where the lock pin 113is disengaged from the lock hole 105 a of the receiving member 105.

One end side of a reclining lock cable 115 is connected to the other endside of the link 112 from the axis 111 via a connector 116. The otherend side of the reclining lock cable 115 is extended to a rotationoperation unit 200 side, which will be described later. When the seat 1is in the specific state (the long state, which will be describedlater), the reclining lock cable 115 restrains the reclining operationunit 100 in an inoperable manner by being pulled from the rotationoperation unit 200 side.

That is, the reclining lock cable 115 swings the link 112 in the counterclockwise direction around the axis 111 in FIG. 9 and FIG. 10 byresisting the biasing force of the spring member 114. Accordingly, sincethe lock pin 113 fits into the lock hole 105 a of the receiving member105, the operation lever 104 is restrained in an inoperable manner. Notethat the reclining lock cable 115 corresponds to “transmission means” ofthe present invention.

As shown in FIG. 7 and FIG. 8 , component parts of the recliningoperation lock mechanism 110 arranged on the housing 101 are covered bya cover-like lid 101 a. An arc-shaped guide groove 101 b centered on theaxis 111 of the link 112 is formed in the housing 101 and the lid 101 a.An axis 117, which pivotably supports the connector 116 to the other endof the link 112, movably fits into the guide groove 101 b, and a swingcentered on the axis 111 of the link 112 is regulated.

<Regarding Orientation of Seat 1>

The seat device 10 can convert the state of the seat 1 between the longstate (refer to FIG. 6 , FIG. 2 ) in which the back of the seat issubstantially parallel to and along a wall A, and a cross state (referto FIG. 1 ) in which the back of the seat is substantially orthogonal tothe wall A. Here, for the cross state, there are one cross state (referto FIG. 1 ), and a reverse cross state that is 180 degrees in theopposite direction to the one cross state. As shown in FIG. 15 , when itis assumed that the long state of the seat 1 has a rotation angle of 0degrees as an original position, the rotation angle of the one crossstate is 90 degrees, and the rotation angle of the reverse cross stateis −90 degrees. Note that the back of the seat is synonymous with theback of the backrest 3. Hereinafter, when collectively referring to theone cross state and the reverse cross state, they are merely written asthe cross state.

<Leg Stand 11>

As shown in FIG. 6 , the leg stand 11 is fixed onto the floor surfacenear the wall A in the cabin. The leg stand 11 is formed by combiningframe members into the shape of a stand that is long in the direction(front and back direction) substantially orthogonal to the wall A.Although an upper surface side of the leg stand 11 is substantiallyhorizontal, and this upper surface side is surrounded by both side ends12 and 12, forming the long sides, and a rear end portion, forming ashort side on the rear side (wall A side), the front side (aisle side)is opened.

The leg stand 11 is arranged so that its rear end portion is close toand substantially parallel to the wall A, and both side ends 12 and 12are substantially orthogonal to the wall A and extend toward the aisleside. Note that, in addition to the sliding mechanism 14, which will bedescribed next, related parts such as a stopper for regulating theadvance and retract range and the rotation direction of the underframe30 are provided in the upper surface side of the leg stand 11.

<Sliding Mechanism 14>

As shown in FIG. 6 , the movable stand 20 is attached to the uppersurface side of the leg stand 11 via the sliding mechanism 14, so as tobe able to advance and retract in the direction substantially orthogonalto the wall A. The sliding mechanism 14 includes a pair of guide rails14 a and 14 a that are provided inside both side ends 12 and 12 of theleg stand 11. The pair of guide rails 14 a and 14 a are parallel to andoppose to each other along both the long sides of the upper surface ofthe leg stand 11, and both side portions 21 and 21 of the movable stand20, which will be described next, directly and slidably fit inside therespective guide rails 14 a.

<Movable Stand 20>

As shown in FIG. 6 , the movable stand 20 is substantially horizontallyarranged on the upper surface side of the leg stand 11, and is formed bycombining frame members into a rectangular framework shape. Both sideends 21 and 21, forming the long sides of the movable stand 20, slidablyfit inside the aforementioned pair of guide rails 14 a and 14 a. Thus,the movable stand 20 can be slid so as to advance or retract in thedirection substantially orthogonal to the wall A. The rotation mechanism40 that rotates the seat 1 about the rotation axis is provided at asubstantially center of the movable stand 20.

<Rotation Mechanism 40>

The rotation mechanism 40 supports the underframe 30 of the seat 1 onthe movable stand 20 so as to be rotatable in the forward and backwarddirections in a substantially horizontal surface. The rotation mechanism40 is formed as a unit in which, for example, a pair of inner and outerring-shaped turntables are rotatably combined with each other byinterposing a bearing, etc. between them. In this rotation mechanism 40,the outer turntable is fixed to the moving table 20, and the innerturntable is fixed to the underframe 30.

The rotation axis, which serves as the rotation center of the seat 1, isthe center line of the rotation mechanism 40, and does not have aphysical substance in the present embodiment. As shown in FIG. 4 , therotation mechanism 40 includes a motor 41, which is a power source. Themotor 41 is provided with a reducer, and a drive gear in its output axisis rotatably engaged with a sprocket 42 centered on the rotation axisprovided in the underframe 30 side. Note that the rotation mechanism 40also allows the seat to be manually rotated.

<Underframe 30>

As shown in FIG. 6 , the seat 1 is attached to the underframe 30, andthe underframe 30 is supported by the rotation mechanism 40 on themovable stand 20. The underframe 30 is formed by, for example, a metalplate that corresponds to a bottom surface of the seating portion 2.Although described above, the sprocket 42 with which the drive gear ofthe motor 41 rotatably engages is integrally provided in the bottomsurface side of the underframe 30.

<Interlocking Mechanism>

Additionally, the seat device 10 includes an interlocking mechanism (notshown) that interlocks the rotation and advancement and retraction ofthe seat 1, so that the seat 1 does not interfere with the wall A, whenconverting the seat 1 to the long state, the one cross state, and thereverse cross state.

When the seat 1 is rotated with the underframe 30, the interlockingmechanism converts the rotation of the underframe 30 into linear motion,transmits the linear motion to the movable stand 20, and makes themovable stand 20 move in a linear direction so as to be close to orseparated from the wall A together with the underframe 30. Although thekind of such an interlocking mechanism is not particularly limited,specifically, for example, the invention already proposed by the presentapplicant and described in Japanese Patent Laid-Open No. 2018-187971 maybe utilized, or, although not published, the invention proposed inJapanese Patent Application No. 2019-239066, etc. may be utilized.

<Rotation Lock Mechanism 60>

The seat device 10 includes a rotation lock mechanism 60 thatunrotatably restrains the underframe 30 (seat) in each rotation positionof the long state, the one cross state, and the reverse cross state.Since the rotation lock mechanism 60 unrotatably locks the underframe 30to the leg stand 11, the movable stand 20 is also inevitably restrainedto the leg stand 11 so as not to be able to advance and retract.

As shown in FIG. 6 , the rotation lock mechanism 60 includes a lock pin61 that can protrude up and down from the leg stand 11 side to theunderframe 30, and locking holes 62 a, 62 b, and 62 c that are providedin the underframe 30, and with and from which the lock pin 61 areengaged and released. A total of three locking holes 62 a, 62 b, and 62c are provided in a long side along the back of the seat, and both shortsides along the seat of the substantially rectangular underframes 30,respectively.

The lock pin 61 is incorporated in a unit 60 a, and the unit 60 a isfixed near the rear end of the upper surface side of the leg stand 11.The lock pin 61 is operated between a lock position at which the lockpin 61 can protrude upward from the upper surface side of the leg stand11 to project upward and fit into the locking holes 62 a, 62 b, and 62c, and a lock release position at which the lock pin 61 retractsdownward to be released from the locking holes 62 a, 62 b, and 62 c.

When the seat 1 is converted into the long state, the one cross state,and the reverse cross state, the lock pin 61 unrotatably restrains theseat 1 by fitting into the locking holes 62 a, 62 b, and 62 c on theunderframe 30 side to which the lock pin 61 vertically corresponds atthe respective positions. That is, in the long state, the lock pin 61fits into the locking hole 62 a in one long side of the underframe 30.Additionally, in the one cross state, the lock pin 61 is inserted intoand engaged with the locking hole 62 b in one short side of theunderframe 30. Furthermore, in the reverse cross state, the lock pin 61fits into the locking hole 62 c in the other short side of theunderframe 30.

As shown in FIG. 13 and FIG. 14 , the unit 60 a in which the lock pin 61is incorporated is provided with each of a spring member (not shown)that always urges the lock pin 61 to project upward to the lockposition, and a link 60 b that makes the lock pin 61 resist the biasingforce of the spring member to retract to the downward lock releaseposition.

The lock pin 61 is configured to be normally maintained in the lockposition by the biasing force of the spring member, but to retract inthe lock release position against the biasing force of the springmember, when the link 60 b is pulled by each operating cable. Here, theother end side of the operating cable for manual operation is extendedto the rotation operation unit 200 provided in the leg stand 11 side.Although described later, when the operating cable 206 (refer to FIG. 11) is pulled by an operation in the rotation operation unit 200, therestraint of the rotation lock mechanism 60 is released.

On the other hand, for example, the motor 41 of the rotation mechanism40 also serves as the power source for pulling the operating cable forelectric operation. That is, the motor 41 includes a clutch, and isconfigured to be able to switch between an operation for rotating theseat by the rotation mechanism 40, and an operation for retracting thelock pin 61 to release the lock, by switching of the clutch. Note that adetailed description of the clutch of the motor 41 is omitted, since theconfiguration regarding the clutch of the motor 41 is common.

The rotation lock mechanism 60 according to the present embodiment isconfigured such that, when the seat 1 is in the long state, therestraint by the rotation lock mechanism 60 cannot be released by amanual operation in the rotation operation unit 200, and can be releasedonly by an electric operation by the motor 41. Here, the electricoperation is performed by a crew or station employee of a vehicle, andthe manual operation is mainly performed by a passenger.

<Rotation Operation Unit 200>

Additionally, the rotation lock mechanism 60 is provided with therotation operation unit 200 for performing a release operation of therestraint by the lock pin 61. As shown in FIG. 1 , the rotationoperation unit 200 is unitized by incorporating each part in one housing201, and is fixed to an attaching portion 22 (refer to FIG. 6 ) hangingfrom the front end side of the movable stand 20.

As shown in FIG. 1 (a), FIG. 2 (a), FIG. 11 , and FIG. 12 , the rotationoperation unit 200 includes a step pedal 204 swingably supported by alower end of a supporting bracket 202 fixed to the front surface side ofthe housing 201 via an axis 203. A tip side of the step pedal 204 can beswung in the front and back directions, with the axis 203, to which itsbase end side is pivotably supported, being the swing center. Note thatthe step pedal 204 corresponds to a “pedal” of the present invention.

The step pedal 204 is swung between a using position (refer to FIG. 11 )at which the tip side protrudes forward of the housing 201, and ahousing position (refer to FIG. 12 ) at which the tip side withdrawsupward. The step pedal 204 is normally urged to protrude forward to bein the using position via the spring member 205. Here, when the steppedal 204 is in the using position, an operation of stepping on this torelease the restraint by the rotation lock mechanism 60 is enabled, butwhen the step pedal 204 is in the housing position, the operation ofreleasing the restraint by the rotation lock mechanism 60 is disabled.Note that the spring member 205 corresponds to “biasing means” of thepresent invention.

The base end side of the step pedal 204 is connected to the other endside of the operating cable 206 for manual operation extended to therotation lock mechanism 60 side via a connector. Here, when the steppedal 204 in the using position is stepped downward, the operating cable206 is pulled and the lock pin 61 (refer to FIG. 13 ) is retracteddownward, and the locked state of the rotation lock mechanism 60 isreleased.

Additionally, a pin-shaped engaged portion 207 projecting in bothdirections at a position eccentric from the axis 203 is fixed to thebase end side of the step pedal 204. The engaged portion 207 isconnected to the other end side of the reclining lock cable 115extending from the reclining operation lock mechanism 110 side via aconnector. Here, when the engaged portion 207 is engaged with anengaging portion 211, which will be described next, the reclining lockcable 115 is pulled, and the lock pin 113 of the reclining operationlock mechanism 110 projects upward, and the reclining operation unit 100is restrained to disable the operation.

<Rotation Operation Blocking Mechanism 210>

Additionally, the rotation operation unit 200 is provided with arotation operation prevention mechanism 210 that disables the releaseoperation of the restraint by the rotation operation unit 200. Therotation operation prevention mechanism 210 disables the operation ofthe step pedal 204 when the seat 1 is in the long state. The long statehere corresponds to a “specific state where the seat 1 is at onerotation angle” in the present invention.

As shown in FIG. 11 and FIG. 12 , the rotation operation preventionmechanism 210 includes the engaging portion 211 provided in the legstand 11, which is the fixed side of the seat 1, and the engaged portion207 provided in the rotation operation unit 200 in the movable side ofthe seat 1. The engaging portion 211 is arranged in the front end of thebottom surface side of the leg stand 11, and is formed in a bracketshape that protrudes diagonally upward toward the front.

The engaged portion 207 is provided in the pin shape at the positioneccentric from the axis 203 in the base end side of the step pedal 204as described above. This engaged portion 207 is set to precisely engagewith the engaging portion 211 when the seat 1 in the long state(specific state). Since the step pedal 204 is swung to be in the housingposition against the biasing force of the spring member 205 when theengaged portion 207 is engaged with the engaging portion 211, therelease operation in the rotation operation unit 200 is disabled. At thesame time, the reclining operation unit 100 is restrained to disable theoperation.

<Operation of Seat Device 10>

Hereinafter, based on FIG. 15 , the operation of converting the state ofthe seat 1 will be described. First, as shown in FIG. 15 (a), when theunderframe 30 (seat 1) is in the long state, the rotation axis (rotationmechanism 40) of the underframe 30 is most retracted (close) to the wallA side. Here, the long side of the underframe 30 (the back of the seat)is substantially parallel to and along the wall A, and the rotationangle is 0 degrees.

<<Restraint of Rotation Operation of Seat 1>>

When the seat 1 is in the long state, the underframe 30 is restrained todisable the rotation with respect to the movable stand 20 by therotation lock mechanism 60. That is, as shown in FIG. 6 , the lock pin61 of the rotation lock mechanism 60 fits into the locking hole 62 a inthe one long side of the underframe 30. Here, since the lock pin 61protrudes from the leg stand 11, which is the fixed side of the seat 1,the seat 1 is not only restrained to disable the rotation, but alsosimultaneously restrained to disable advancement and retraction.

As shown in FIG. 2 , when the seat 1 is in the long state, the releaseoperation in the rotation operation unit 200 is disabled by the rotationoperation prevention mechanism 210. That is, in the long state, themovable stand 20 is most retracted (close) to the wall A side, and thefront end side of the movable stand 20 overlaps with the front end sideof the leg stand 11. With this positional relationship, as shown in FIG.2 (c), the engaged portion 207 of the step pedal 204 in the movablestand 20 is engaged with the engaging portion 211 in the leg stand 11.Then, the step pedal 204 is swung to be in the housing position at whichthe step pedal 204 is upright against the biasing force of the springmember 205, and is restrained in the housing position.

Accordingly, when the seat 1 is in the long state, the step pedal 204 isnot only displaced to the housing position at which the operation isdisabled, but also firmly held in the housing position by the engagementrelationship between the engaging portion 211 and the engaged portion207. Thus, in the long state, the release operation in the rotationoperation unit 200 is disabled. With such a simple configuration, therotation operation of the seat 1 by a seated person can be reliablyprevented in the long state.

<<Restraint of Reclining Operation of Backrest 3>>

Additionally, when the seat 1 is in the long state, the recliningoperation in the reclining operation unit 100 is disabled by thereclining operation lock mechanism 110. To be more specific, when thestep pedal 204 is swung upward by the engagement of the engaged portion207 to the engaging portion 211, the reclining lock cable 115 connectedto the engaged portion 207 is pulled, and the reclining operation unit100 is restrained to disable the operation.

That is, as shown in FIG. 10 , when the reclining lock cable 115 ispulled, the link 112 is swung in the counter clockwise direction aroundthe axis 111 in FIG. 10 against the biasing force of the spring member114. Then, the lock pin 113 in the one end side of the link 112 projectsupward to fit into the lock hole 105 a in the receiving member 105integrated with the operation lever 104 in the initial position.

Accordingly, when the seat 1 is in the long state, the recliningoperation by the reclining operation unit 100 is disabled, and thebackrest 3 cannot be tilted by the reclining mechanism 50. With such asimple configuration, in the long state, the reclining operation of thebackrest 3 by a seated person can be reliably prevented, and thebackrest 3 can be prevented from being carelessly tilted to interferewith the wall A.

<<Conversion from Long State to One Cross State>>

As shown in FIG. 15 (a) to FIG. 15 (c), in order to convert theunderframe 30 (seat 1) into the one cross state from the long state (therotation angle 90 degrees), first, it is necessary to release therestraint of the rotation by the rotation lock mechanism 60. Here, theoperation of disengaging the lock pin 61 from the locking hole 62 acannot be performed by the operation of the step pedal 204 as describedabove, and is performed by the electric operation utilizing the power ofthe motor 41.

In the long state shown in FIG. 15 (a), when the underframe 30 isrotated by the motor 41 to the forward direction (the counter clockwisedirection in FIG. 15 ) as shown in FIG. 15 (b) after releasing therestraint by the rotation lock mechanism 60, the underframe 30 isrotated while moving forward by interlocking mechanism. That is, theunderframe 30 is rotated while being rotated in the forward directionand moving forward to the aisle side, so as not to interfere with thewall A.

As shown in FIG. 15 (c), when the underframe 30 reaches the one crossstate (the rotation angle 90 degrees), in FIG. 6 , the lock pin 61 ofthe rotation lock mechanism 60 fits into the locking hole 62 b in theone short side of the underframe 30. Accordingly, the underframe 30(seat 1) is unrotatably restrained in the one cross state.

<<Release of Restriction of Rotation Operation of Seat 1>>

When the seat 1 is in the cross state, the restraint to disable theoperation of the rotation operation unit 200 by the rotation operationprevention mechanism 210 is released. That is, in the cross state shownin FIG. 15 (c), the movable stand 20 is most advanced (separated) fromthe wall A side, and the front end side of the movable stand 20 islocated farther forward from the front end side of the leg stand 11. Inthis positional relationship, as shown in FIG. 11 , the engaged portion207 of the step pedal 204 in the movable stand 20 is not engaged withand separated from the engaging portion 211 in the leg stand 11. Thus,the step pedal 204 protrudes forward to be in the using position by thebiasing force of the spring member 205.

At this time, the seated person of the seat 1 can release the restraintby the rotation lock mechanism 60 by stepping on the step pedal 204.That is, in FIG. 11 , when the step pedal 204 is stepped on to be swung,the operating cable 206 is pulled, the lock pin 61 (refer to FIG. 13 )is retracted downward, and the locked state of the rotation lockmechanism 60 is released. Accordingly, the seated person can manuallyrotate the seat 1.

<<Release of Restriction of Reclining Operation of Backrest 3>>

Additionally, when the seat 1 is in the cross state, the restraint todisable the operation of the reclining operation unit 100 by thereclining operation lock mechanism 110 is also released. That is, asdescribed above, in the cross state, as shown in FIG. 11 , the engagedportion 207 of the step pedal 204 in the movable stand 20 is not engagedwith and separated from the engaging portion 211 in the leg stand 11.Thus, the step pedal 204 protrudes forward to be in the using positionby the biasing force of the spring member 205, and the reclining lockcable 115 is in a state where the reclining lock cable 115 is notpulled.

Accordingly, as shown in FIG. 9 , in the reclining operation lockmechanism 110, the link 112 is in a state where the lock pin 113 is notmade to project upward, by the biasing force of the spring member 114.Thus, the lock pin 113 has come out of the lock hole 105 a in thereceiving member 105 integrated with the operation lever 104, and therestraint to disable the operation of the operation lever 104 isreleased to enable the reclining operation. Therefore, the seated personcan tilt the backrest 3 to an arbitrary angle by the reclining mechanism50, and can improve seating comfort.

<<Conversion from One Cross State to Reverse Cross State>>

In the one cross state shown in FIG. 15 (c), when the underframe 30 isrotated to the backward direction (the clockwise direction in FIG. 15 )after the restraint of the rotation lock mechanism 60 is released, theunderframe 30 advances or retracts while, for example, being rotated bythe interlocking mechanism, whose illustration is omitted. Subsequently,as shown in FIG. 15 (d), in a state where the underframe 30 istemporarily held at the position to which the underframe 30 has advancedin a state parallel to the long state, the underframe 30 is directlyrotated to the opposite direction without advancing and retracting.

As shown in FIG. 15 (e), when the underframe 30 reaches the reversecross state (the rotation angle −90 degrees), the lock pin 61 of therotation lock mechanism 60 fits into the locking hole 62 c in the othershort side of the underframe 30, and the underframe 30 is restrainedagain to disable the rotation. Such conversion of the seat 1 into thereverse cross state from the one cross state can be performed by notonly the manual operation, but also by the electric operation. Notethat, in order to return the seat 1 from the reverse cross state to theone cross state, and further from the one cross state to the originallong state, the inverse operations of the aforementioned conversion fromthe long state to the one cross state, and from the one cross state tothe reverse cross state may be performed, respectively.

<Configuration and Effects of Present Invention>

Although the embodiment of the present invention has been describedabove, the present invention is not limited to the aforementionedembodiment. The present invention derived from the aforementionedembodiment will be described below.

First, the present invention is

the seat device 10 that can convert the state of the seat 1, including

the rotation lock mechanism 60 that can restrain the seat 1 at each of aplurality of rotation angles, the seat being rotatable about therotation axis,

the rotation operation unit 200 that performs the release operation ofrestraint by the rotation lock mechanism 60, and

the rotation operation prevention mechanism 210 that disables therelease operation in the rotation operation unit 200, when the seat 1 isin the specific state of one of the rotation angles,

the rotation operation prevention mechanism 210 including

the engaging unit 211 provided on the fixed side of the seat 1, and

the engaged unit 207 that is provided in the rotation operation unit 200on the movable side of the seat 1, and disables the release operation inthe rotation operation unit 200 by being engaged with the engaging unit211 when the seat 1 is in the specific state.

In the present seat device 10, when the seat 1 is in the long state,which is the specific state, although the back of the seat is close tothe wall A, the rotation of the seat 1 by a passenger is disabled, sothat the passenger cannot freely change the position. Here, it isnecessary to release the restraint by the rotation lock mechanism 60 bythe rotation operation unit 200 for rotating the seat 1. Therefore, therotation of the seat 1 can be disabled by disabling the operation of therotation operation unit 200 by the rotation operation preventionmechanism 210.

In the rotation operation prevention mechanism 210, when the seat 1 isin the long state, the release operation of the rotation operation unit200 is disabled by engaging the engaged portion 207 in the rotationoperation unit 200 on the movable side of the seat 1 with the engagingportion 211 in the fixed side of the seat 1. With such a mechanicalengagement relationship between the engaging portion 211 and the engagedportion 207, the rotation of the seat 1 by a seated person can bedisabled only when the seat 1 is in the long state, with a simpleconfiguration, and without using electric power.

Additionally, as the present invention,

the rotation operation unit 200 can be displaced between the usingposition at which the release operation is enabled, and the housingposition at which the release operation is disabled, and

when the seat 1 is in the specific state, the rotation operationprevention mechanism 210 displaces the rotation operation unit 200 fromthe normal using position to the housing position, and restrains therotation operation unit 200 in the housing position, by engaging theengaged portion 207 with the engaging portion 211.

In this manner, in the present seat device 10, when the seat 1 is in thelong state, which is the specific state, the rotation operation unit 200is displaced from the normal using position to the housing position, byengaging the engaged portion 207 with the engaging portion 211.Therefore, the operation itself of the rotation operation unit 200 by aseated person cannot be performed, and the rotation of the seat 1 can beregulated in a manner that is easily understood by the seated person.

Moreover, the rotation operation unit 200 is not only merely displacedto the housing position, but also is restrained so as not to bedisplaced from the housing position by the engagement relationshipbetween the engaging portion 211 and the engaged portion 207. Therefore,it is also possible to reliably prevent an erroneous operation ofcarelessly returning the rotation operation unit 200 to the usingposition by the seated person.

Additionally, the present invention includes

the rotation mechanism 40 that rotates the seat 1 about the rotationaxis, and

the sliding mechanism 14 that advances and retracts the seat 1 togetherwith the rotation mechanism 40 from the fixed side,

wherein the state of the seat 1 can be converted by interlocking of therotation mechanism 40 and the sliding mechanism 14 between

the long state where the back of the seat is substantially parallel toand along the wall A, and

the cross state where the back of the seat is separated from the wall Ain the direction substantially orthogonal to the long state, and

the specific state of the seat 1 corresponds to the long state.

Accordingly, as described in the above embodiment, it becomes possibleto directly apply the present seat device 10 to general rotary seatsmounted in railroad cars.

Additionally, the present invention includes

the leg stand 11 fixed on the floor surface, as the fixed side of theseat 1, and

the movable stand 20, as the movable side of the seat 1, the movablestand 20 being supported by the leg stand 11 via the sliding mechanism14 so as to be able to advance and retract, the seat 1 being rotatablysupported by the movable stand 20 via the rotation mechanism 40,

wherein the engaging portion 211 is provided in the leg stand 11, and

the rotation operation unit 200 and the engaged portion 207 are providedin the movable stand 20.

In this manner, in the present seat device 10, it is possible to achievethe layout that makes the engaging portion 211 and the engaged portion207 of the rotation operation prevention mechanism 210 the optimumcomponents, among the minimum required components of the seat device 10.

Furthermore, as the present invention,

the rotation operation unit 200 includes the pedal 204 that is supportedwith the base end side being the rotation center, so as to be able to beswung between the using position at which the pedal 204 protrudesforward on the one end side of the movable stand 20, and the housingposition at which the pedal 204 is upwardly upright,

the engaged portion 207 is provided at the position eccentric from therotation center of the pedal 204, and

while the pedal 204 is normally maintained in the using position by thebiasing means 205, when the engaged portion 207 is engaged with theengaging portion 211, the pedal 204 is swung to be in the housingposition against the biasing force of the biasing means 205, and isrestrained in the housing position.

In this manner, in the present seat device 10, among the minimumrequired components of the seat device 10, it is possible to easilyachieve the rotation operation unit 200, and the engaging portion 211and the engaged portion 207 of the rotation operation preventionmechanism 210 with a simple configuration.

Although the embodiments have been described above with the drawings,the specific configuration is not limited to these embodiments, and evenwhen there are modification and addition in the scope not departing fromthe gist of the present invention, they are included in the presentinvention.

For example, the shapes of the leg stand 11, the movable stand 20, andthe underframe 30 are not limited to those shown. Additionally, althoughthe example of the seat 1 for two persons has been described, the seat 1may be for three persons or one person. In addition, the conversion ofthe state of the seat is not limited to the long state, the one crossstate, and the reverse cross state.

INDUSTRIAL APPLICABILITY

The present invention can be widely utilized as a seat device for chairsfor theaters, home, and office, in addition to the seat 1 for vehiclesinstalled in cabins of railroad cars, airplanes, automobiles, marinevessels, etc.

REFERENCE SIGNS LIST

-   10 . . . Seat device-   11 . . . Leg stand-   14 . . . Sliding mechanism-   20 . . . Movable stand-   30 . . . Underframe-   40 . . . Rotation mechanism-   50 . . . Reclining mechanism-   60 . . . Rotation lock mechanism-   100 . . . Reclining operation unit-   104 . . . Operation lever-   105 . . . Receiving member-   110 . . . Reclining operation lock mechanism-   113 . . . Lock pin-   200 . . . Rotation operation unit-   204 . . . Step pedal-   207 . . . Engaged portion-   210 . . . Rotation operation prevention mechanism-   211 . . . Engaging portion

1. A seat device that can convert a state of a seat, comprising: arotation lock mechanism that can restrain the seat at each of aplurality of rotation angles, the seat being rotatable about a rotationaxis; a rotation operation unit that performs a release operation ofrestraint by the rotation lock mechanism; and a rotation operationprevention mechanism that disables the release operation in the rotationoperation unit, when the seat is in a specific state of one of therotation angles, the rotation operation prevention mechanism comprising:an engaging unit provided on a fixed side of the seat; and an engagedunit that is provided in the rotation operation unit on a movable sideof the seat, and disables the release operation in the rotationoperation unit by being engaged with the engaging unit when the seat isin the specific state.
 2. The seat device according to claim 1, whereinthe rotation operation unit can be displaced between a using position atwhich the release operation is enabled, and a housing position at whichthe release operation is disabled, and when the seat is in the specificstate, the rotation operation prevention mechanism displaces therotation operation unit from the normal position to the housingposition, and restrains the rotation operation unit in the housingposition, by engaging the engaged portion with the engaging portion. 3.The seat device according to claim 1, further comprising: a rotationmechanism that rotates the seat about the rotation axis; and a slidingmechanism that advances and retracts the seat together with the rotationmechanism from the fixed side, wherein the state of the seat can beconverted by interlocking of the rotation mechanism and the slidingmechanism between a long state where a back of the seat is substantiallyparallel to and along a wall, and a cross state where the back of theseat is separated from the wall in a direction substantially orthogonalto the long state, and the specific state of the seat corresponds to thelong state.
 4. The seat device according to claim 3, further comprising:a leg stand fixed on a floor surface, as the fixed side of the seat; anda movable stand, as the movable side of the seat, the movable standbeing supported by the leg stand via the sliding mechanism so as to beable to advance and retract, the seat being rotatably supported by themovable stand via the rotation mechanism, wherein the engaging portionis provided in the leg stand, and the rotation operation unit and theengaged portion are provided in the movable stand.
 5. The seat deviceaccording to claim 4, wherein the rotation operation unit includes apedal that is supported with a base end side being a rotation center, soas to be able to be swung between the using position at which the pedalprotrudes forward on one end side of the movable stand, and the housingposition at which the pedal is upwardly upright, the engaged portion isprovided at a position eccentric from the rotation center of the pedal,and while the pedal is normally maintained in the using position bybiasing means, when the engaged portion is engaged with the engagingportion, the pedal is swung to be in the housing position against abiasing force of the biasing means, and is restrained in the housingposition.